Core鈥揝hell Nanoparticles As Building Blocks for the Bottom-Up Production of Functional Nanocomposites: PbTe鈥揚bS Thermoelectric Properties
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- 作者：Maria Ib谩帽ez ; Reza Zamani ; St茅phane Gorsse ; Jiandong Fan ; Silvia Ortega ; Doris Cadavid ; Joan Ramon Morante ; Jordi Arbiol ; Andreu Cabot
- 刊名：ACS Nano
- 出版年：2013
- 出版时间：March 26, 2013
- 年：2013
- 卷：7
- 期：3
- 页码：2573-2586
- 全文大小：1111K
- 年卷期：v.7,no.3(March 26, 2013)
- ISSN：1936-086X
文摘
The bottom-up assembly of nanocrystals provides access to a three-dimensional composition control at the nanoscale not attainable by any other technology. In particular, colloidal nanoheterostructures, with intrinsic multiphase organization, are especially appealing building blocks for the bottom-up production of nanocomposites. In the present work, we use PbTe鈥揚bS as the model material system and thermoelectricity as the paradigmatic application to investigate the potential of the bottom-up assembly of core鈥搒hell nanoparticles to produce functional nanocomposites. With this goal in mind, a rapid, high-yield and scalable colloidal synthetic route to prepare grams of PbTe@PbS core鈥搒hell nanoparticles with unprecedented narrow size distributions and exceptional composition control is detailed. PbTe@PbS nanoparticles were used as building blocks for the bottom-up production of PbTe鈥揚bS nanocomposites with tuned composition. In such PbTe鈥揚bS nanocomposites, synergistic nanocrystal doping effects result in up to 10-fold higher electrical conductivities than in pure PbTe and PbS nanomaterials. At the same time, the acoustic impedance mismatch between PbTe and PbS phases and a partial phase alloying provide PbTe鈥揚bS nanocomposites with strongly reduced thermal conductivities. As a result, record thermoelectric figures of merit (ZT) of 1.1 were obtained from undoped PbTe and PbS phases at 710 K. These high ZT values prove the potential of the proposed processes to produce efficient functional nanomaterials with programmable properties.